Water quality mediated community variations and niche differentiation of macroinvertebrates in Qingyijiang River Basin, China

Abstract

In order to understand the community characteristics of macroinvertebrates in Qingyijiang River, a survey was conducted in September 2020 and July 2021. In this paper, the change of water quality was analyzed by using water environment quality and comprehensive index, and the niche of macroinvertebrates was further analyzed by using the substitution method based on the occurrence frequency of species, simulated null distribution of niche breadth and Mantel test. The results are revealed as follows: (1) There were significant changes in the number of macroinvertebrates between 2020 and 2021, but no significant changes in community composition (percentage of taxa); (2) The comprehensive evaluation results of water quality showed that the water environment of Qingyijiang River Basin in 2020 and 2021 was generally cleanest-clean. This also reflects that a series of water environmental governance measures in China have achieved remarkable results; (3) The constraints of natural and social status should also be taken into account when selecting the biological indices; (4) The results of ecological niche partitioning of macroinvertebrates show that the survival strategies of the generalists species are characterized by strong tolerance to water pollution, strong aggressive nature and mobility while the specialists species are Gastropoda with poor mobility, species that are relatively intolerant to water pollution, clingers and rare species. Mantel tests showed that only the ammonium nitrogen in 2020 had a significant effect on the specialists species; (5) When the water environment tends to be stable, clean and healthy, the specialists species can also become the generalists species.

Keywords

• Macroinvertebrate
• Niche
• Community structure
• Water quality evaluation
• Environmental factors